stl % is flawed as an indicator of likelihood of a steal occurring in a given play as it is actually a measure of what % of a team's steals a given player was responsible for not a measure of how many times a player created a steal per play (let alone a direct head-to-head metric of steal vs opp TOV) - the one guy who occasionally creates steals on a team otherwise not prone to doing so will have a higher stl% than a true ball hawk amongst ball hawks

in other words it's a bad metric in the first place and it's being used in a way that doesn't really apply - they'd be better off using a steals per minutes played figure in its stead

That isn't how STL% is measured. If a player gets 3 steals per 100 possessions by the opponents, he will have a STL% of 3 (regardless of how many steals his teammates get).

Does rebounding work like that also? For example, 94-95 Dennis Rodman has a OReb% of 20.1%. Does this mean that he is responsible for grabbing 20% of his teams total offensive boards, or does it mean that every 100 missed shots by his team while he is on the court, he will grab 20 offensive rebounds?

or does it mean that every 100 missed shots by his team while he is on the court, he will grab 20 offensive rebounds?

This is what the stat measures. Now, it doesn't exactly show up that way in the sim because there's not a nice, neat 100% between all of your offensive rebounders & all of the defensive rebounders. So it's really 20% of the cumulative between your 5 oreb% & defense's 5 dreb% plus whatever bonuses gained from having a "significant advantage" in 1v1 matchups & the penalty the shooter faces to their rebounding.

That's why more is better and you shouldn't aim for any specific number when it comes to rebounding.

OR%: Offensive Rebounding Percentage = 100 * (ORB * (Tm MP / 5)) / (MP * (Tm ORB + Opp DRB)). Offensive rebounding % is an estimate of the percentage of available offensive rebounds a player grabbed while he was on the floor.